I'm tired of bottling and want to move to kegging. And I know that you can fill some bottles from the keg and cap them, for easy sharing.
BUT, I also have this thing where I'm brewing the same beer every year and storing some, for 18 years. And I'm concerned that beer that has been kegged, then dispensed into a bottle and then capped and stored won't keep very well.
Is this concern founded? And if so, what should I do? Move to kegging for everything but this beer? Stick with bottling even though I hate it? Some third option?
I don't think your concerns are very well-founded.
Pros of kegging and filling bottles from the keg:
1. You can (and should) think of a keg as a giant bottle. Whatever "conditioning" by yeast you think is happening in the bottle, will also happen in the keg. You can store a keg at warmer temperatures if you want to speed this up. Keg is not some magical space where yeast dies and you are forcing some weird CO2 molecules which are totally synthetic, as opposed to "natural" and "organic" CO2 molecules that yeast produces.. You can add sugar to kegs if you like too btw.
2. Not sure how you store your bottles, but unless you gave a dedicated cellar or fridge, they are subject to daily fluctuations. But it takes a lot more thermal energy to heat up and cool down 5 Gallon of liquid than it takes 12 oz. And there is zero exposure to light. Zero.
3. You can purge your keg prior to transferring beer a lot better than you can ever fill a bottle. And with bottling gun you can purge your bottles with CO2 as well. If oxygen is your concern, I will bet you that a closed transfer under CO2, into a well-purged (fill with starsan and empty) keg, and then filling from the keg into a CO2 purged bottle, will give you an order of magnitude oxygen than just filling bottles from the bucket.
4. You will completely avoid sediment from bottle fermentation.
5. You can dial in your carbonation level precisely instead of guessing, then keg when it's perfect.
6. You can make additions to the beer (dry hopping, fruit, oak, vanilla, coffee etc.) and keg when it's perfect to your taste.
7. You can taste/drink your beer in any amounts as these processes are happening.
8. No bottle bombs, ever.
9. Perfect for competition (no sediment, precisely dialed in profile and carbonation).
10. You can use beergun to purge many other things with CO2 - like when kettle-souring, headspace of a fermenter, during cold-crashing, etc.
Cons:
1. You will incur extra costs. Kegs, beer gun, regulators, CO2, connectors, lines, etc.
2. You will drink your beer faster.
3. Your friends and neighbor will show up to your house to "fill up growlers".
4. Kegging saves quite a bit of time so you will brew more often
5. I can't come up with cons #5-10 - anyone else, please help?